Generally, electronic components using a ceramic material, such as a capacitor, an inductor, a piezoelectric element, a varistor, a thermistor, and the like, include a ceramic body formed of the ceramic material, internal electrodes formed in the ceramic body, and external electrodes installed on surfaces of the ceramic body to be connected to the internal electrodes.
Recently, in accordance with miniaturization and multifunctionalization of electronic products, multilayer ceramic capacitors have also tended to be miniaturized and multifunctionalized. Therefore, a multilayer ceramic capacitor having a small size and high capacitance has been demanded.
As a method of simultaneously accomplishing miniaturization and an increase in capacitance of the multilayer ceramic capacitor, there is a method of increasing the numbers of dielectric layers and electrode layers stacked in the multilayer ceramic capacitor by decreasing thicknesses of the dielectric layers and the electrode layers. Currently, a thickness of the dielectric layer is about 0.6 μm, and technology for decreasing the thickness of the dielectric layer is being continuously developed.
In addition, in order to accomplish the increase in the capacitance of the multilayer ceramic capacitor, a material having a high dielectric constant has been demanded. A typical material used in the multilayer ceramic capacitor is barium titanate (BaTiO3), but it is difficult to develop a material for increasing a dielectric constant due to a limitation of inherent characteristics of the barium titanate.
Therefore, research into technology of implementing a high dielectric constant by doping additives on a surface of the barium titanate (BaTiO3) or reforming the surface of the barium titanate (BaTiO3) has been conducted, but there is no remarkable achievement.
Meanwhile, it has been known that there is an influence of a domain wall of 90° in a principle of implementing a dielectric constant. Therefore, research into technology for improving the tetragonality of barium titanate (BaTiO3) has been continuously conducted.
A dielectric has a core-shell structure due to additives added to a dielectric material of the multilayer ceramic capacitor in order to improve reliability of the multilayer ceramic capacitor and secure sinterability of the multilayer ceramic capacitor, but the domain wall is not present in a shell, such that there is a limitation in implementing a high dielectric constant.